WASHINGTON – The U.S. Supreme Court on Monday agreed to hear what could become a landmark case on the limits of the president’s power to make appointments – along with a defining moment in the career of a Buffalo-born lawyer and the make-or-break point for a Buffalo-based ruling on Internet free speech.

In a case called National Labor Relations Board v. Canning, the justices will decide whether presidents can fill high-level positions without Senate confirmation whenever the Senate is in recess – as they always have – or whether presidents can make “recess appointments” only during the breaks between the Senate’s yearlong sessions.

The case, in which the justices will also consider the narrower question of whether the president can make recess appointments when the Senate is convening every three days in pro forma session, will be one of the biggest of the court’s next term, which starts in October.

The justices’ decision, expected late this year or in the first half of 2014, could determine whether Buffalo native Richard F. Griffin Jr. was legally appointed to the NLRB in 2012.

In addition, the case could determine whether that board has made hundreds of rulings that are invalid because they were decided by illegally appointed board members – including a case involving Hispanics United of Buffalo that said, for the first time, that people can discuss their jobs on Facebook without getting fired.

Most importantly, though, the justices will likely resolve an important constitutional question that takes on greater urgency in harshly partisan times such as these: how free the president is to do an end-around to avoid a clash with the Senate over top administration appointments.

“It’s an extremely important case,” said Matthew D. Dimick, a law professor at the University at Buffalo. “It’s not just about these labor board decisions – it’s about the power of the president to make appointments.”

The Constitution gives presidents the power to temporarily fill top administration posts without Senate approval when the Senate is out of session. Presidents have long defined that to mean whenever the Senate is on one of its frequent breaks.

Federal courts always defined the recess appointment power that way, too – that is, until a case involving Noel Canning, a Washington State Pepsi distributor, went to the U.S. Court of Appeals for the D.C. Circuit.

Having lost a union case at the NLRB, Canning argued the decision was invalid because three of the board members who decided it – including Griffin – were illegally appointed when President Obama named them to the board Jan. 4, 2012, after the Senate had begun its session for the year but while it was on a short break.

Last Jan. 25, an appeals court panel agreed with Canning, saying the president can only make recess appointments during the Senate’s end-of-the-year recesses. What’s more, two of those judges ruled that to be filled by recess appointment, both the vacancy and the appointment must take place on the same Senate break.

The ruling enraged the Obama administration, which appealed to the Supreme Court.

“The court of appeals’ decision would dramatically curtail the scope of the president’s authority under the Recess Appointments clause,” the administration said in asking the court to hear the appeal. “It would deem invalid hundreds of recess appointments made by presidents since early in the nation’s history.”

It said those “invalid” appointments would include “three Cabinet secretaries, five court of appeals judges, ten district court judges, a director of central intelligence, a chairman of the Federal Reserve, numerous members of multi-member boards, and holders of a variety of other critical government posts.”

Republicans argue that Obama went too far when, during a short Senate break, he appointed Griffin, Sharon Block and a third NLRB member who has since resigned.

And one of the most important of them originated in Buffalo.

Fired after her boss saw their Facebook conversation about working conditions at Hispanics United of Buffalo, Mariana Cole-Rivera and four of her former colleagues at the small Buffalo nonprofit filed a complaint with the NLRB to try to regain their jobs and back pay. Last December, they won.

What’s more, they won the first-ever federal edict on how far workers can go when discussing their work on social media.

“Employees have a protected right to discuss matters affecting their employment amongst themselves,” the NLRB ruled.

But now that NLRB ruling and many others are under legal question because they were decided by board members who may not be serving legally.

“It becomes an issue for us to raise on appeal,” said Rafael O. Gomez, the Buffalo lawyer who is defending Hispanics United.